Quantitative magnetic resonance imaging (qMRI) methods provide standardizable and objective measures for characterizing brain development and abnormalities in young children. However, motion is a significant problem for applying extended qMRI studies in young children and has limited the ability to perform studies in these populations. This project will further develop, optimize and evaluate technologies for multicomponent relaxometry. The technique will be specifically optimized for pediatric imaging by dramatically reducing the acquisition time and utilizing a novel image reconstruction method that reduces motion artifacts. These optimized imaging technologies will be evaluated in young children. This project will provide a set of protocols, software tools, and strategies for investigating healthy and abnormal brain development in both clinical and research pediatric populations.